If y varies directly as x, find the constant of variation k and the direct variation equation for the situation.
y=0.3 when x=0.6
find the constant of variation k.
k=
(round to one decimal place.)
then write the direct variation equation.

Alright! I've seen quite a few of these so I thought I'd get them out of the way and help you out! :).

Direct variation is simple. The formula you'll use to find the constant K is as follows:

y = kx

Once you've established your formula you simply plug in:

.3 = (k)(.6)

Then you solve for k by dividing both sides by (.6) thus getting:

(.3/.6) = k  OR  (1/2) = k

Your direct variation equation is your standard formula with only K plugged in:

y = (1/2)x

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.